137 



Augaptilus longicaudatus Wolfenden, 1904, p. 112. 



Augaptilus longicaudatus Sars, \c)0^{l>], p. 4. 



Augaptilus longicaudatus Esterly, 1905, p. 188, fig. 41. 



Augaptilus longicaudatus Pcarson, 1906, p. 28. 



Augaptilus longicaudatus Farran, 190S, p. 78. 



Augaptilus longicaudatus van Breemen, 1908, p. 135, fig. 154. 



Six specimens of this form were found in the plankton collected with the Hensen vertical 

 net at the following stations. 



Stat. 185 (1536 metres to surface), 3 specimens. — Stat. 203 (1500 metres to surface), 2 spe- 

 cimens. — Stat. 276 (750 metres to surface), 1 specimen. 



Augaptilus longicaudatus can be distinguished from the other members of the genus, 

 by its moderately long abdomen and furcal joints. It is closely related to Augaptilus kecticus 

 and Augaptilus megalurus. It differs from the former species, by the furcal joints being five 

 times longer than broad, and from the latter, by the equal length of the second and third 

 abdominal segments. In Augaptilus hecticus the furcal joints are three times longer than broad. 

 The third abdominal segment of Augaptilus megalurus is distinctly shorter than the second segment. 



This species appears to have a moderately wide distribution. 



5. Augaptilus palumboi Giesbrecht. 



Augaptilus palumboi Giesbrecht, 1889, p. 813. 



Augaptilus palumboi Giesbrecht, 1893, p. 400, pis. 27, 28 & 39. 



Augaptilus palumboi Giesbrecht & Schmeil, 1898, p. 122. 



Augaptilus palumboi I. C. Thompson, 1903, p. 28. 



Augaptilus palumboi Sars, 1905^), p. 4. 



Augaptilus palumboi Farran, 1908, p. 75. 



Augaptilus palumboi van Breemen, 1908, p. 134, fig. 151. 



Eight specimens of this species were found in the plankton collected with the Hensen 

 vertical net at the following stations. 



Stat. 118 (900 metres to surface), 1 specimen. — Stat. 128 (700 metres to surface), 1 spe- 

 cimen. — Stat. 141 (1500 metres to surface), 1 specimen. — Stat. 143 (1000 metres to 

 surface), 2 specimens. — Stat. 148 (1000 metres to surface), 1 specimen. — Stat. 203 (1500 

 metres to surface), 2 specimens. 



Augaptilus palumboi is readily distinguished by its small size, by the short second 

 abdominal segment, and by the anal segment being twice the length of the second segment. 



This species was originally found in the Pacific Ocean. It has been recorded within 

 recent years from the North Atlantic. 



6. Augaptilus placitus nov. sp. Plate XLII, figs. 10 — 19. 



Female — length 10 mm. 



Seen from above, the body is elongate ovate, and rather slender. The last thoracic 

 segment is contracted posteriorly, and the distal ends are somewhat narrowly rounded. Viewed 



i37 



SIBOGA-EXPEDITIE XXIXa. l8 



